Insoluble cement solution



Sept. 12, 1933. H. e. HALLORAN INSOLUBLE CEMENT SOLUTION Filed April 9, 1932 wad-07'.

Patented Sept. i2, 1933 UNITED STATES PATENT OFFlCE 6 Claims.

The invention to be hereinafter described relates to an insoluble or waterproof cement and the process of making the same.

Heretofore glue or cement has been made from leather, but it has been considered essential first to detan the same, and the glue thus produced is soluble in water. By the process of the present invention the leather is not detanned, but on the contrary the tanning agent is retained in the leather and an insoluble cement is produced. In the practice of the process the leather with its tanning agent therein is subjected to heat and pressure in the presence of water, resulting in an insoluble cement solution which may be employed in making insoluble fibrous compositions of matter in which the fiber may be, for example, cotton, wool, silk, sisal ramie, kapok, wood pulp, leather fiber or paper. A sheet or bat of such unwoven fibers may be impregnated with the insoluble oement solution so that it will coat the fibers, fill the interstices between them and solidify into a hard, tough mass. If the product is to be flexible, a plasticizer may be introduced into the cement such, for example, as rubber latex, water dispersed rubber, oils, or soft resins.

The character of the invention may be best understood by reference to the following description of the process as practiced with the apparatus shown in the accompanying drawing,

' wherein:

Fig. 1 is a diagrammatic view of the apparatus;

Fig. 2 is a section through a portion of the impregnator cylinder;

Fig. 3 is a side view of the rotary disk for said cylinder;

Fig. 4 is a vertical section through said cylinder; and

Fig. 5 is a side view of the disk having the arcuate channels therein.

Referring to the drawing, the apparatus shown therein comprises a closed digester 1 provided with a steam jacket 3 receiving steam from a suitable source through a pipe 5 and discharging through a pipe '7. Water may be admitted into the digester through a pipe 9 under the control of a valve 11. At the top of the digester is a head 13 and a pipe 15 projects from the head and carries a steam gage 17 and safety valve 18.

Leather with its tanning agent remaining therein and water are introduced into the digester. The leather may be scrap leather trimmed from tanned hides, and may be readily obtained in large quantities from tanners, i. e. or other sources. The leather and water should be subjected to heat to develop suflicient pressure in the digester to put the leather into a solution. The amount of pressure developed by heating the water in the digester will vary according to the character of the leather, and may for example, be about fifteen pounds. The time required to produce this solution depends upon the size of the pieces of leather and the character of the leather. If the leather is new and in very small pieces, the solution is obtained in a few minutes, whereas, if the leather is old, a longer time is required.

After the solution is obtained, it may be drawn from the digester through a pipe 19 and delivered to a storage tank 21. If the product is to be flexible, a plasticizer may be mixed with the solution. To this end a mixing tank 23 may be provided connected by a pipe 25 with the storage tank. A pump 27 of suitable construction may be employed to pass the solution from the storage tank to the mixing tank. The latter may be supplied with suitable mixing blades (not shown) of usual known construction. The plasticizer used may be rubber or other latex or rubber dispersed in Water. When a plasticizer is used of the latex type, water dispersed rubber and sulphur are added for vulcanizing purposes. Under heat the plasticizer becomes vulcanized and adds to the strength of the product.

To impregnate a fibrous sheet with the solution, in the present instance, a cylinder 29 is provided comprising a shell 31 of wood or other suitable material. Encircling the shell is a drum 33 of sheet metal having reticulations distributed throughout the same. It will be undersood, however, that any suitable screen may be employed. The drum is spaced from the shell, and partitions 35 divide the space into pockets 37.

Projecting inward from and communicating with the pockets are elbow pipes 39 having ends connected to and extending through a rotary disk 40. In contact with a face of said disk is a fixed disk 41 having a long arcuate channel 43 and a shorter arcuate channel 45 therein. A pipe 47 extends from the groove 43 to a suction pump 49, and a pipe 51 extends from the groove 45 to a blower 53.

The fibrous sheet may be conducted to the impregnator cylinder by a conveyer 55, and may pass over the cylinder to a conveyer 57. To apply the cement solution to the fibrous sheet, a pipe 59 is led from the mixing tank 23, and in the present instance delivers the solution to three sprinklers 61. The cylinder may be rotated by any suitable means, and as the sheet passes over the cylinder it will become impregnated with the solution delivered from the sprinklers. As

the elbow pipes 39 referred to, pass along and register with the channel 43, suction will be established in the pockets communicating with such pipes, and thiswill draw the solution into the sheet, so that it will be thoroughlyimpregnated therewith and any excess solution will be removed. When the elbow pipes come into registration with the shorter cylinder channel 45, a draft will be blown through such pipes and don the sheet from the cylinder. This sheet impregnating operation should be carried on in an atmosphere of sufficient humidity to prevent evaporation of the solution and to prevent its accumulating on the screen surface of the cylinder or other parts.

The impregnated sheet on leaving the conveyer 57 may pass between a pair of press rolls 63, thereby to press the solution impregnated fibers into a solid sheet. Then the sheet may be carried by a conveyer 65 into a dryer 67 where it passes progressively over a series of conveyers 69. Hot air may be drawn through the dryer by a fan 71. Since this fan is of usual construction, it is unnecessary to show and describe the same further in detail herein. The sheet which is to be impregnated with the cement solution may be formed of two or more layers of unspun fibers or bats, preferably with the fibers of the sheets extending in transverse relation to one another. The sheet may be woven or unwoven, and any suitable material may be employed.

The insoluble fibrous sheet or composition of matter produced by this process has many uses. It is a good substitute for leather, being lighter, cheaper, and more durable, and is not soluble in water. It may be employed for inner and outer soles of shoes and many other purposes.

It will be understood that the invention is not limited to the specific process described herein, and that various deviations may be made therefrom without departing from the spirit and scope of the appended claims.

What is claimed is:

1. The process of making a waterproof composition of matter, characterized by subjecting leather, with its tanning agent therein, to heat and pressure in the presence of water, thereby to produce a waterproof cement solution comprising the resultant product of leather and its tanning agent dissolved in water.

2. The process of making a waterproof composition of matter, characterized by introducing into a closed digester, water, and leather with its tanning agent therein, and heating the digester to generate steam therein and develop pressure to produce a waterproof cement solution'comprising the resultant product of leather and its tanning agent dissolved in water.

3. The process of making a waterproof composition of matter, characterized by subjecting a mass of scrap leather with its tanning agent therein to heat andpressure in the presence of water, thereby to produce a waterproof cement solution comprising the resultant product of leather and its tanning agent dissolved in water.

4. The process of making Waterproof cement, characterized by subjecting leather, with its tanning agent therein, to heat and pressure in the presence of water, thereby to produce a waterproof cement, and adding a plasticizer to the cement to give it flexibility.

5. A waterproof cement solution comprising the resultant product of leather with all its tanning agent dissolved in water.

6. A waterproof cement solution suitable for impregnating fibres comprising the resultant product of leather with all its tanning agent dissolved in water with added latex and sulphur.

HENRY G. HALLORAN. 

